<!DOCTYPE html>
<meta name=help href="https://privacycg.github.io/storage-partitioning/">
<title>Helper frame</title>

<script>
  const usageDetails = async () =>
    (await navigator.storage.estimate()).usageDetails.indexedDB || 0;

  let details = {};

  window.addEventListener("message", async event => {
    if (event.data === "get-details") {
      details.source = "same-site";
      details.init = await usageDetails();
      event.source.postMessage(details, event.source.origin);
    }
  });

  window.addEventListener("load", async () => {
    if (parent.opener) {
      details.source = "cross-site";
      details.init = await usageDetails();
      parent.opener.postMessage(details, parent.opener.origin);
    }
  });

  window.parent.postMessage("iframe-is-ready", window.parent.origin);
</script>
